PLCL/PCL Dressings with Platelet Lysate and Growth Factors Embedded in Fibrin for Chronic Wound Regeneration

Johanka Táborská,1 Andreu Blanquer,2,3 Eduard Brynda,1 Elena Filová,2 Lenka Stiborová,1 Věra Jenčová,4 Kristýna Havlíčková,4 Zuzana Riedelová,1 Tomáš Riedel1 1Department of Chemistry and Physics of Surfaces and Biointerfaces, Institute of Macromolecular Chemistry, Czech Academy of Sciences, Prague, Czech Republic; 2Department of Biomaterials and Tissue Engineering, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic; 3Departament de Biologia Cellular, Fisiologia i Immunologia, Universitat Autonoma de Barcelona, Bellaterra, Spain; 4Department of Chemistry, Technical University of Liberec, Liberec, Czech RepublicCorrespondence: Tomáš Riedel, Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovskeho namesti 2, 162 00 Prague 6, Czech Republic, Tel +420 296 809 333, Email riedel@imc.cas.czIntroduction: The formation of diabetic ulcers (DU) is a common complication for diabetic patients resulting in serious chronic wounds. There is therefore, an urgent need for complex treatment of this problem. This study examines a bioactive wound dressing of a biodegradable electrospun nanofibrous blend of poly(L-lactide-co-ϵ-caprolactone) and poly(ϵ-caprolactone) (PLCL/PCL) covered by a thin fibrin layer for sustained delivery of bioactive molecules.Methods: Electrospun PLCL/PCL nanofibers were coated with fibrin-based coating prepared by a controlled technique and enriched with human platelet lysate (hPL), fibroblast growth factor 2 (FGF), and vascular endothelial growth factor (VEGF). The coating was characterized by scanning electron microscopy and fluorescent microscopy. Protein content and its release rate and the effect on human saphenous vein endothelial cells (HSVEC) were evaluated.Results: The highest protein amount is achieved by the coating of PLCL/PCL with a fibrin mesh containing 20% v/v hPL (NF20). The fibrin coating serves as an excellent scaffold to accumulate bioactive molecules from hPL such as PDGF-BB, fibronectin (Fn), and α-2 antiplasmin. The NF20 coating shows both fast and a sustained release of the attached bioactive molecules (Fn, VEGF, FGF). The dressing significantly increases the viability of human saphenous vein endothelial cells (HSVECs) cultivated on a collagen-based wound model. The exogenous addition of FGF and VEGF during the coating procedure further increases the HSVECs viability. In addition, the presence of α-2 antiplasmin significantly stabilizes the fibrin mesh and prevents its cleavage by plasmin.Discussion: The NF20 coating supplemented with FGF and VEGF provides a promising wound dressing for the complex treatment of DU. The incorporation of various bioactive molecules from hPL and growth factors has great potential to support the healing processes by providing appropriate stimuli in the chronic wound.Keywords: human platelet lysate, diabetic ulcer, fibrin coating, growth factors, nanofibers, bioactive dressing